1. Field of the Invention
The present invention relates to a recording condition determining method, program and medium, an information recording apparatus and an information recording system. Particularly, the present invention relates to a recording condition determining method for determining an optimum recording condition upon recording information on an information recording medium, a program used in an information recording apparatus, a storage medium on which such program is stored, an information recording apparatus that records information on an information recording medium, and an information recording system including an information recording apparatus and an information processing apparatus.
2. Description of the Related Art
In recent years and continuing, with the improvement of the functions of the personal computer (referred to as PC hereinafter), it is becoming possible to handle AV (Audio-Visual) information such as music and images in the PC. Since the information amount of AV information is very large, attention is being drawn to optical disks such as the CD (compact disk) and DVD (digital versatile disk) as information recording media. In turn, the price of such media is falling, and the optical disk apparatus as an information recording apparatus is becoming very popular as one of the peripheral apparatuses of the PC. In an optical disk apparatus, a laser beam is irradiated so as to form microscopic light spots on a recording surface of an optical disk on which surface a spiral track or concentric tracks are formed to record and erase information, and information is replayed (reproduced) based on light reflected from the recording surface. The optical disk apparatus has an optical pickup device as a device for irradiating the laser beam onto the recording surface of the information recording medium as well as receiving the reflected light from the recording surface.
Normally, the optical pickup device includes a light source for emitting the laser beam at a predetermined light emission power (output), an optical system for leading the laser beam emitted from the light source to the recording surface of the information recording medium and leading the laser beam reflected from the recording surface to a predetermined light receiving position, and an optical receiver placed at the light receiving position, for example.
The optical disk has mark (pit) regions and space regions that have differing reflection rates, and information is recorded on the optical disk based on the lengths of the mark regions and space regions and their combination. Thus, in recording information on an optical disk, the light emission power of the laser beam emitted from the light source is controlled so that mark regions and space regions can be formed on the recording surface at their respective predetermined positions in their respective predetermined lengths.
For example, in the case of recording information on a recordable optical disk such as the CD-R (CD-recordable), the DVD-R (DVD-recordable), and the DVD+R (DVD+recordable) that contain organic dye in their recording layers (referred to as ‘dye disk’ hereinafter), a mark region is formed by raising the light emission power to heat and melt the dye so that the properties and shape of a substrate portion that is in contact with the irradiated dye are changed. As for the formation of a space region, the light emission power is lowered to a level equivalent to that used in a replaying operation so that the properties and shape of the substrate will not be changed. As a result, the mark region has a lower reflection rate compared to the space region.
Also, in the case of recording information on a rewritable optical disk such as the CD-RW (CD-rewritable), DVD-RW (DVD-rewritable), and DVD+RW (DVD+rewritable) that contain a special alloy in their recording layers (referred to as ‘phase-change disk’ hereinafter), a mark region is formed by heating the alloy to a first temperature and then rapidly cooling the heated alloy so that it will be in an amorphous (non-crystalline) state. As for the formation of a space region, the alloy is heated to a second temperature (<first temperature) after which it is gradually cooled to be in a crystalline state. Thus, the mark region has a lower reflection rate compared to the space region.
The light emission power required for the formation of the mark region (also referred to as ‘recording power’ hereinafter) greatly depends on the recording speed. Namely, with the increase of the recording speed, there is a growing tendency for the recording power to be increased. However, as the recording power is increased, this may exceed the power capacity of the light source, and the service life of the light source may be shortened as a result. In turn, a number of methods for setting the recording speed according to the power capacity of the light source have been proposed in the prior art (e.g., refer to Japanese Laid-Open Patent Publication No.2002-251738, and Japanese Laid-Open Patent Publication No.2001-67672).
However, according to the methods disclosed in the above prior art documents, when the recording power for obtaining a predetermined recording quality is not within the permissible range of the light source, the recording power is lowered so that the recording speed is greatly reduced and the recording time is increased even when the influence of the original recording power on the service life of the light source may be relatively small.